Faculty Bibliography

The Global Navigation Satellite System (GNSS) is commonly used for outdoor positioning. However, its effectiveness diminishes in urban canyons and indoor environments attributed to signal blockage. This study aims to explore the potential of GNSS signals penetrating indoor spaces through windows and to enhance indoor positioning with Three-Dimensional Mapping-Aided (3DMA) GNSS, a concept generally applied outdoors. The research employs a 3D model of a corridor with manually labeled window locations to predict satellite visibility within indoor areas. The study integrates Pedestrian Dead Reckoning (PDR) with an indoor Shadow-matching (I-SM) technique, utilizing an Extended Kalman Filter (EKF) to improve positioning accuracy. One of the findings indicates that the proposed method significantly enhances positioning performance and its availability, achieving a root mean square error (RMSE) that is 2 m better than using PDR alone or single epoch I-SM. The study concludes that integrating GNSS with I-SM technique and PDR can optimize an indoor positioning solution and highlights the potential for improved navigation solutions in complex urban environments.

BACKGROUND:Individuals with sensory processing disorders (SPDs) face challenges in wayfinding due to heightened sensitivity to environmental stimuli like noise and lighting. Although sensory maps have aided SPD individuals by aligning navigational routes with sensory needs, standardized protocols for creating these maps are lacking, with current methods largely qualitative. OBJECTIVE:This study aimed to establish a standardized, quantitative protocol for sensory map creation, evaluating sound, brightness, and crowding density in a healthcare setting to enhance map precision and support future automation. METHODS:Sensory data were collected from the 1st and 17th floors of a large urban ambulatory care center in New York City. A qualitative spatial audit was initially conducted, followed by quantitative measurements of sound (decibels), brightness (lux), and crowding density at designated nodes. Using Python, we developed Voronoi diagrams to visualize intensity distributions across floorplans, applying statistical methods to ensure data accuracy and consistency. RESULTS:Qualitative assessments identified high-stimulus areas, particularly in the main lobby and elevator zones, which aligned closely with quantitative findings. Brightness peaked in central, naturally lit areas, while noise levels were highest near heating, ventilation, and air conditioning (HVAC) systems and entry points. The quantitative method enabled a more nuanced representation, enhancing map detail and reliability. CONCLUSIONS:The developed quantitative protocol offers a robust framework for sensory mapping, improving accessibility for individuals with SPDs in complex spaces. This approach holds potential for automation, addressing current reproducibility limitations and advancing inclusive design in public and healthcare settings.

PURPOSE/UNASSIGNED:Navigating urban environments poses significant challenges for individuals who are blind or have low vision, especially in areas affected by construction. Construction zones introduce hazards such as uneven surfaces, barriers, hazardous materials, excessive noise, and altered routes that obstruct familiar paths and compromise safety. Although navigation tools assist in trip planning, they often overlook these temporary obstacles. Existing hazard detection systems also struggle with the visual variability of construction sites. METHODS/UNASSIGNED:We developed a computer vision-based assistive system integrating three modules: an open-vocabulary object detector to identify diverse construction-related elements, a YOLO-based model specialised in detecting scaffolding and poles, and an optical character recognition module to interpret construction signage. RESULTS/UNASSIGNED:In static testing at seven construction sites using images from multiple stationary viewpoints, the system achieved 88.56% overall accuracy. It consistently identified relevant objects within 2-10 m and at approach angles up to 75°. At 2-4 m, detection was perfect (100%) across all angles. Even at 10 m, six of seven sites remained detectable within a 15° approach. In dynamic testing along a 0.5-mile urban route containing eight construction sites, the system analysed every frame of a first-person walking video. It achieved 87.26% accuracy in distinguishing construction from non-construction areas, rising to 92.0% with a 50-frame majority vote filter. CONCLUSION/UNASSIGNED:The system can reliably detect construction sites in real time and at sufficient distances to provide advance warnings, enabling individuals with visual impairments to make safer mobility decisions, such as proceeding with caution or rerouting.

BACKGROUND/UNASSIGNED:Outdoor navigation poses significant challenges for people with blindness or low vision, yet the role of gaze behaviour in supporting mobility remains underexplored. Fully sighted individuals typically adopt consistent scanning strategies, whereas those with visual impairments rely on heterogeneous adaptations shaped by residual vision and experience. METHODS/UNASSIGNED:We conducted a comparative eye-tracking study of fully sighted, low vision, blind, and fully blind participants navigating outdoor routes. Using a wearable eye tracker, we quantified fixation counts, fixation rate, fixation area, direction, peak fixation location, and walking speed. RESULTS/UNASSIGNED:Walking speed declined systematically with worsening vision. Fixation count increased with greater impairment, reflecting slower travel times and more frequent sampling. Fixation rate differed across groups, though between-group differences were generally not significant between most groups. Fixation spatial coverage decreased along the continuum of vision loss. Fixation patterns were most consistent in the fully sighted group. Peak fixation locations were centred in fully sighted participants but shifted outward and became more variable with impairment. CONCLUSION/UNASSIGNED:Gaze strategies during navigation form a graded continuum across vision groups, with fully sighted and fully blind participants at opposite poles and low vision and blind groups spanning the middle. Visual acuity alone does not predict functional gaze use, as rehabilitation experience and adaptive strategies strongly shape behaviour. These findings highlight the need for personalised rehabilitation and assistive technologies, with residual gaze patterns offering insight into mobility capacity and training opportunities for safer navigation.IMPLICATIONS FOR REHABILITATIONDistinct Residual Vision Patterns: This research reveals that residual vision patterns differ significantly, with fully sighted individuals exhibiting a consistent fixation pattern while low vision participants show more varied strategies during navigation.Highly Individualised Gaze Behaviours: Low vision participants demonstrate highly individualised gaze behaviours, indicating that a one-size-fits-all approach is inadequate for effective rehabilitation.Tailored Assistive Solutions: Assistive technologies and rehabilitation programs should be designed to address these unique, individualised needs, providing personalised feedback and training to enhance mobility and safety.

AIM/UNASSIGNED:Sensory substitution devices (SSDs) can convert environmental information into an accessible format for people who are blind or have low vision (pBLV). Yet, current SSDs often passively deliver all of the information available with limited user control, potentially leading to confusion and/or cognitive overload. To address this issue, this work proposes a selective, gesture-controlled system intended to improve information relevance and reduce cognitive overload. METHODS/UNASSIGNED:We present Point-To-Tell 2, a system that enables pBLV to privately and efficiently select which information to convey through simple pointing-based gestural control. By integrating a monocular camera with AI-driven pipelines for depth estimation, hand pose tracking, and object detection/segmentation, the system identifies the users' 3D pointing direction and announces the names and distances of objects as they are pointed at, thereby connecting an object's spatial position and identity through hand proprioception. RESULTS/UNASSIGNED:Validation tests in controlled indoor environments show high hand pose tracking accuracy, ensuring reliable ray-casting and object selection despite declining object recognition at longer distances. Distance estimates are stable at close range, though a systematic bias is present. CONCLUSION/UNASSIGNED:This work introduces and technically validates an assistive system designed to improve the usability of assistive technologies by focusing system feedback-potentially reducing users' cognitive load and enhancing their spatial comprehension by leveraging concurrent hand proprioception. Future work will involve user testing and expanding system features to further enhance its practicality across more diverse scenarios.

This study explores the use of virtual reality (VR) as an innovative tool to enhance awareness, understanding of accessibility for persons with vision loss (VL), and acceptance. Through a VR-based workshop developed in collaboration with New York City's Department Of Transportation, participants experienced immersive simulations of VL and related immersive mobility challenges. The methodology included the development of a VR environment, simulations of vision loss, testing with the DOT team during the workshop, and an assessment of changes in participants' knowledge, confidence in addressing accessibility challenges, and overall perception through pre- and post-intervention questionnaires. Participants included urban planners, designers, and architects. Results showed a significant increase in awareness of VL-related challenges that affect design guidelines, as well as improved confidence in addressing such challenges. Participants also expressed strong support for VR as a pedagogical tool, noting its potential for reshaping professional practices, improving capacity building, and enhancing inclusive design. The study demonstrates the effectiveness of VR as an experiential learning platform, fostering empathy and a long-term commitment to integrating VL considerations into urban design. These findings highlight the transformative potential of VR in advancing equity and accessibility in urban environments.

Curbs serve as vital borders that delineate safe pedestrian zones from potential vehicular traffic hazards. Curbs also represent a primary spatial hazard during dynamic navigation with significant stumbling potential. Such vulnerabilities are particularly exacerbated for persons with blindness and low vision (PBLV). Accurate visual-based discrimination of curbs is paramount for assistive technologies that aid PBLV with safe navigation in urban environments. Herein, we investigate the efficacy of curb segmentation for foundation models. We introduce the largest curb segmentation dataset to date to benchmark leading foundation models. Our results show that state-of-the-art foundation models face significant challenges in curb segmentation. This is due to their low precision and recall with poor performance distinguishing curbs from curb-like objects or non-curb areas, such as sidewalks. In addition, the best-performing model averaged a 3.70-s inference time, underscoring problems in providing real-time assistance. In response, we propose solutions including filtered bounding box selections to achieve more accurate curb segmentation. Overall, despite the immediate flexibility of foundation models, their application for practical assistive technology applications still requires refinement. This research highlights the critical need for specialized datasets and tailored model training to address navigation challenges for PBLV and underscores implicit weaknesses in foundation models.

PURPOSE/UNASSIGNED:People with blindness and low vision (pBLV) face challenges in navigating. Mobility aids are crucial for enhancing independence and safety. This paper presents an electronic travel aid that leverages a haptic-based, higher-order sensory substitution approach called Virtual Whiskers, designed to help pBLV navigate obstacles effectively, efficiently, and safely. MATERIALS AND METHODS/UNASSIGNED:Virtual Whiskers is equipped with a plurality of modular vibration units that operate independently to deliver haptic feedback to users. Virtual Whiskers features two navigation modes: open path mode and depth mode, each addressing obstacle negotiation from different perspectives. The open path mode detects and delineates a traversable area within an analyzed field of view and then guides the user in the most traversable direction with adaptive vibratory feedback. Depth mode assists users in negotiating obstacles by highlighting spatial areas with prominent obstacles; haptic feedback is generated by re-mapping proximity to vibration intensity. We recruited 10 participants with blindness or low vision for user testing of Virtual Whiskers. RESULTS/UNASSIGNED:Both approaches reduce hesitation time (idle periods) and decrease the number of cane contacts with objects and walls. CONCLUSIONS/UNASSIGNED:Virtual Whiskers is a promising obstacle negotiation strategy that demonstrates great potential to assist with pBLV navigation.

Curbs separate the edge of raised sidewalks from the street and are crucial to locate in urban environments as they help delineate safe pedestrian zones from dangerous vehicular lanes. However, the curbs themselves are also significant navigation hazards, particularly for people who are blind or have low vision (pBLV). The challenges faced by pBLV in detecting and properly orienting themselves for these abrupt elevation changes can lead to falls and serious injuries. Despite recent advancements in assistive technologies, the detection and early warning of curbs remains a largely unsolved challenge. This paper aims to tackle this gap by introducing a novel, multi-faceted sensory substitution approach hosted on a smart wearable; the platform leverages an RGB camera and an embedded system to capture and segment curbs in real time and provide early warning and orientation information. The system utilizes a YOLOv8 segmentation model which has been trained on our custom curb dataset to interpret camera input. The system output consists of adaptive auditory beeps, abstract sonifications, and speech, which convey curb distance and orientation. Through human-subjects experimentation, we demonstrate the effectiveness of the system as compared to the white cane. Results show that our system can provide advanced warning through a larger safety window than the cane, while offering nearly identical curb orientation information. Future enhancements will focus on expanding our curb segmentation dataset, improving distance estimations through advanced 3D sensors and AI-models, refining system calibration and stability, and developing user-centric sonification methods to cater for a diverse range of visual impairments.

BACKGROUND:Patients with disabilities face widespread barriers to accessing surgical care given inaccessible health systems, resulting in poor clinical outcomes and perpetuation of health inequities. One barrier is the lack of education, and therefore awareness, among trainees/providers, of the need for reasonable accommodations for surgical patients with disabilities. METHODS:We conducted a scoping review of the literature on the current state of disabilities curricula in medical education and graduate residency curriculum. RESULTS:While the literature does demonstrate a causal link between reasonable accommodation training and positive patient-provider relationships and improved clinical outcomes, in practice, disability-focused curricula are rare and often limited in time and to awareness-based didactic courses in medical education and surgical training. CONCLUSIONS:The absence of structured curricula to educate on anti-ableism and care for patients with disabilities promotes a system of structural "ableism." Expanding disability curricula for medical students and trainees may be an opportunity to intervene and promote better surgical care for all patients.